The present invention relates to the recording of information and more particularly to an apparatus for reading and writing information using an electret material.
With the use of electrical computers and other information handling systems increasing at a rapid rate, the demand for a simple, economical and high-speed apparatus for storing large amounts of information has also increased. As a result of this demand, various information storage processes have been investigated. One of these processes has involved the use of "electrets" as the medium for storing electrical charges. As described in U.S. Pat. No. 3,445,824, issued to J. E. Fulenweider on May 20, 1969, a semiconductor information storage device includes a matrix array of rows and columns of conductors disposed on opposite sides of a sheet of dielectric material with the dielectric material in the local regions of cross-overs of the conductors defining bit locations in which information is stored by first heating up the dielectric material at the bit locations and then applying an electrical potential difference between the row and column conductors thereat, while the dielectric material is hardened to form a permanent polarization core electret representing a binary 1 state. The absence of an electret at a bit location represents a binary 0 state. In U.S. Pat. No. 3,276,031, issued to J. Gaynor on Sept. 27, 1966, deformations are formed in a deformable electret layer representing the information to be recorded. The drawback with these prior art storage systems is that their use becomes increasingly difficult as the data density requirement increases. The reading and writing of electret charges in this manner will require proportionately smaller electrode assemblies, thereby increasing the complexity of their circuitry and requiring more sensitive electronics. Because of these problems, older techniques rapidly lose their utility as they reach their limits in either storage density or read-write speed. It is therefore the principal object of this invention to provide an improved system for storing binary information. It is a further object of this invention to provide an improved system for the reading and writing of data on a low-cost, high-capacity storage medium .